1. Field of the Invention
This invention relates to the editing of recorded material (such as audio or video material) and to edit controllers such as audio and/or video edit controllers.
2. Description of the Prior Art
As an example, video edit controllers are used to edit a number of "raw" source video sequences into a final programme or part of a programme. For example, a short news story may contain brief excerpts of a number of different video sequences, possibly including newly captured and older, archived sequences, in order to illustrate different aspects of the news story. A relevant portion or "clip" of each sequence needs to be selected, and the selected portions linked together to form the composite output sequence.
Recently, computer-based non-linear edit controllers have become available. These allow a user to view the source sequences on a computer screen and to select an "in-point" and an "out-point" for each required sequence using the computer keyboard or a cursor control device such as a mouse, joystick or trackerball.
An example of a display screen for such an edit controller is shown schematically in FIG. 1 of the accompanying drawings.
In FIG. 1, a number of source video sequences are stored either on video tape or in a computer-based storage device such as a hard disk. The source sequences are registered with the edit controller, for example by the user indicating where on a video tape that source sequence can be found, or simply by the sequence being copied into the computer-based storage device. The source video sequences are then represented by source icons 20 in an upper area of the display screen. These source video sequences are then all available for editing by the user.
A viewer window 10 is provided for viewing a currently selected source (or output) video sequence. To view a source video sequence the user simply selects the corresponding source icon, for example by double-clicking (using a mouse cursor control device) on the icon. That source sequence can then be viewed in the viewer window, under the control of simulated video tape recorder controls such as play, stop, rewind etc.
When a portion of a source video sequence is selected by the user specifying an in-point and an out-point, that portion is represented in a lower, output area of the screen by a clip icon 30. In contrast to the source icons described above, where the order of display on the display screen simply related to the order in which the source sequences were registered or loaded, the order of the output icons 30 is important. In particular, the order (from left to right) of the icons on the screen represents the order in which the corresponding portions of video sequences will be replayed to for the output edited sequence.
Thus, in the example of FIG. 1, if the user double-clicks on the clip icon 30A, then the whole of the portion A will be displayed, followed immediately by the whole of the portion B, then C and finally D. The composite sequence ABCD forms the edited output programme.
If the user wishes to preview only, say, a latter part of the edited output programme, he could double-click on the clip icon 30C, in which case replay would start from the beginning of clip C, to be followed immediately by clip D.